TOURNAI (BE)
Quarry blast22 February 2023
- Magnitude
- 1.8ML
- Depth
- –
- Belgian time
- 12:59:362023-02-22
- UTC
- 11:59:362023-02-22
Main parameters
| Date and time | 2023-02-22 11:59:36 UTC 2023-02-22 12:59:36 Belgian time |
|---|---|
| Magnitude | ML 1.8 |
| Epicentral coordinates | 50.594° N, 3.457° E Uncertainty ± 7.8 km |
| Event ID | ROB 18850 |
Data source : ROB (Royal Observatory of Belgium)
Last update : 2023-02-25 15:35:58 Belgian time
Location map
- Epicentre
- Station that recorded the event
Arrival times at the stations
Each station first records the P wave, the fastest, then the S wave. The farther a station is from the epicentre, the later the waves reach it and the wider the gap between the two.
- Stations
- 7
- Epicentral distance
- 30.3 – 196.6km
- Mean velocity, P wave
- 5.6km/s
- Mean velocity, S wave
- 3.2km/s
- P wave
- S wave
- Curve fitted to the measurements
Notes and method
Curves: travel time of a direct wave in a homogeneous medium. The velocity of each wave and an origin-time shift, common to both, are fitted to the measurements by least squares. Depth not determined: hypocenter placed at the surface for the calculation. P wave: 6 measurements, root-mean-square deviation 0.31 s. S wave: 4 measurements, root-mean-square deviation 0.25 s.
Stations farther than 120 km are left out of the fit: the first waves to reach them have travelled beneath the crust, through the mantle, where they propagate faster.
Station measurements
P- and S-wave arrivals and ground displacement measured at each station. Click a column heading to change the order.
| km | ° | UTC | UTC | s | |
|---|---|---|---|---|---|
| Belgian seismic network (Royal Observatory of Belgium)7 stations | |||||
| LESLessines | 30.3 | 64 | 11:59:41.61+5.52 s | 11:59:45.27+9.18 s | 3.66 |
| SKQSteenkerque | 44.5 | 82 | 11:59:43.53+7.44 s | 11:59:49.40+13.31 s | 5.87 |
| BRQBracquegnies | 49.8 | 104 | 11:59:44.72+8.63 s | – | – |
| RQRRonquières | 54.4 | 88 | 11:59:45.16+9.07 s | – | – |
| SNFSeneffe | 59.4 | 99 | 11:59:45.92+9.83 s | 11:59:53.71+17.62 s | 7.79 |
| DOUDourbes | 98.2 | 124 | 11:59:53.55+17.46 s | 12:00:06.40+30.31 s | 12.85 |
| KLBKalborn | 196.6 | 105 | 12:00:07.89+31.80 s | – | – |